Samenvatting:This report contains the results of a scoping study performed by ECN wind energy for the Ministry of Economic Affairs of the Netherlands.
The Ministry of Economic Affairs has assigned ECN to determine the optimal wind farm power density, in MW/km, for future offshore wind farms to be installed.
The wind farms considered will be developed after 2023 and for this study assumed to be located in the currently assigned but yet unused wind farm zones west of the presently developed (near shore) wind farm zones.
In consultation with the ministry we assumed an area of 12 * 30 km, thus 360 km, where wind farms were modelled with 10 and 15 MW wind turbines. With each (virtual) wind turbine type 3 different wind farms were modelled and evaluated.
The wind farm designs have a wind farm power density of 4, 7 and 10 MW/km. The wind turbines applied in the wind farm designs are based on the following assumptions:
A rotor power density of 330 W/m, resulting in a
• 10 MW wind turbine with a rotor diameter of 196 m and a
• 15 MW wind turbine with a rotor diameter of 241 m
A hub height, above MSL, of 30 + 0.5 rotor diameter.
The wind turbine power curve and axial thrust curve have been determined using ECNs rotor design model BOT.
The wind conditions are assumed to be based on the measurements of the IJmuiden Ver meteorological mast.
The results show that the optimal wind farm power density is 4.66 MW/km2 for a 10 MW wind turbine and 5.06 MW/km2 for a 15 MW wind turbine.
A sensitivity study for some of the input / intermediate results show that the result is rather robust and not sensitive to uncertainty of the yield, the capital cost or the cost of O&M and the weighted average cost of capital.